Keith Alexander Takes a Walk on the Underside—of Bridges—with Teetering Tourists in Tow

For some people no mountain is too high, no ocean too deep. For environmental artist Keith Alexander, no bridge is too long. In a career spanning the last 2½ years, the 28-year-old has made a profession of traversing bridges—53 so far, more than 40 of them in his hometown of Chicago.

Big deal, you say. Anyone can cross a bridge. Ah, but not with the Alexander technique. This guy takes a decidedly alternate route, slithering underneath the suspended structures. An ex-sculptor who graduated with honors from the University of Illinois-Chicago, Alexander considers his hobby an art form—and he loves to have company. "I provide the bridge," he says. "The people provide the art."

Granted, inching along narrow girders in the dead of night with turbulent waters churning below isn't for everyone. "I've taken close to 300 people on climbs with me," says Alexander, who charges $20 per person. "Some chicken out." Larry Adams, 23, an employee of Chicago's City News Bureau, managed to reach the other side of the city's La Salle Street Bridge before losing his lunch. "It was scary but amazing," he says. "I might do it again."

Alexander struts his stuff with no special equipment. Although he has never been hurt, there have been some touchy moments. After a seven-hour trek from Marin County to San Francisco via the flip side of the Golden Gate, he couldn't find a way off and had to crawl back whence he'd come—a mile and a half along a 10-inch beam, 250 feet above the Bay.

Anita Alexander, 58, Keith's mother, is not amused. "He is my only son, and I'd like to see him stay alive," she says. "Fortunately, he's a good swimmer." Before Keith went to Britain last year, Anita called Scotland Yard to warn them. London Bridge became off-limits, but Alexander found a surmountable site in Wales. Just back from Australia's Sydney Harbor Bridge, Keith is girding his loins for a new jaunt. "I hope to get to Paris," he says sotto voce. "Please, don't tell my mom."